Deboeuf S, Lajeunesse E, Dauchot O, Andreotti B
Institut de Physique du Globe de Paris, 4 place Jussieu, 75252 Paris Cedex 05, France.
Phys Rev Lett. 2006 Oct 13;97(15):158303. doi: 10.1103/PhysRevLett.97.158303. Epub 2006 Oct 12.
Unconfined granular flows along an inclined plane are investigated experimentally. During a long transient, the flow gets confined by quasistatic banks but still spreads laterally towards a well-defined asymptotic state following a nontrivial process. Far enough from the banks a scaling for the depth averaged velocity is obtained, which extends the one obtained for homogeneous steady flows. Close to jamming it exhibits a crossover towards a nonlocal rheology. We show that the levees, commonly observed along the sides of the deposit upon interruption of the flow, disappear for long flow durations. We demonstrate that the morphology of the deposit builds up during the flow, in the form of an underlying static layer, which can be deduced from surface velocity profiles, by imposing the same flow rule everywhere in the flow.
对沿倾斜平面的无约束颗粒流进行了实验研究。在长时间的瞬态过程中，流动被准静态堤岸限制，但仍通过一个非平凡过程横向扩展至一个明确的渐近状态。在离堤岸足够远的地方，得到了深度平均速度的标度关系，这扩展了均匀稳定流的标度关系。接近堵塞时，它表现出向非局部流变学的转变。我们表明，在流动中断时通常在沉积物侧面观察到的堤岸，在长时间流动时会消失。我们证明，沉积物的形态在流动过程中以底层静态层的形式形成，这可以通过在流动中各处施加相同的流动规则，从表面速度剖面推导出来。
